12th Amendment

The 12th Amendment (Amendment XII) to the US Constitution was ratified by the US Congress on 15 June 1804 to solve problems with the electoral process. The amendment allowed for a presidential candidate to choose his own vice-presidential running mate, replacing the Electoral College's ability to elect the vice-president (the runner-up in every election automatically became vice-president). In the United States presidential election, 1804, Thomas Jefferson chose George Clinton as his running mate, the first time that a US presidential nominee was able to choose his vice-president.